Background: Strength training (ST) may be beneficial for preservation of lean tissue, increasing bone mineral content, decreasing falls, and enhancing quality of life. Strength training is becoming an appropriate mode of exercise for cardiac rehabilitation (CR) patients. One method for determining optimal exercise intensity for safe and effective ST requires one repetition maximum (1RM) testing. Clinicians may be reluctant to perform 1RM testing in CR patients because of potential muscle soreness/injury and adverse hemodynamic responses in deconditioned patients. The purpose of this investigation was to perform 1RM testing in CR patients and determine muscle soreness/injury rate.
Methods: Seventy-four CR patients stratified by risk (low n = 30, intermediate n = 21, high n = 23) and sex (males = 55, females = 19) participated. Subject's ages ranged from 39 to 76 years and time from procedure ranged from 19 days to 2 years. No patient had ever undergone 1RM testing. The method of Kraemer and Fry was used to assess 1RM. High-risk patients' heart rates/rhythms and blood pressures were monitored. Patients were evaluated for occurrence of muscle soreness/injury immediately after 1RM testing and on days 2 and 7 using a soreness scale developed by Shaw et al. Muscle soreness/injury was considered significant if a patient reported altering or stopping physical activities.
Results: No injury or significant muscle soreness occurred as a result of 1RM testing. No abnormal heart rate/rhythm or blood pressure responses occurred in high-risk patients.
Conclusions: Results indicate that with proper technique, 1RM testing may be performed in CR patients without injury or significant muscle soreness.